U.S. patent application number 13/041412 was filed with the patent office on 2011-06-30 for starch film and method for manufacturing starch foam.
This patent application is currently assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE. Invention is credited to Chei Kao, Ching-Chih Lai, Jyi Hsiang Lee, Chin-Ying Tsai.
Application Number | 20110159267 13/041412 |
Document ID | / |
Family ID | 44187917 |
Filed Date | 2011-06-30 |
United States Patent
Application |
20110159267 |
Kind Code |
A1 |
Lee; Jyi Hsiang ; et
al. |
June 30, 2011 |
STARCH FILM AND METHOD FOR MANUFACTURING STARCH FOAM
Abstract
A biodegradable starch film is provided. The biodegradable
starch film includes a starch which is cross-linked by means of a
cross-linking agent. The cross-linking agent comprises glycidyl
methacrylate 2,3-epoxypropyl methacrylate (GMA), octenyl succinyl
anhydride (OSA), or dodecyl succinic anhydride (DDSA) or
combinations thereof. The cross-linking agent is 1 to 10 weight
parts based on the starch of 100 weight parts. Furthermore, a
method for manufacturing starch foam is also provided.
Inventors: |
Lee; Jyi Hsiang; (Hsinchu
City, TW) ; Kao; Chei; (Hsinchu City, TW) ;
Lai; Ching-Chih; (Hsinchu, TW) ; Tsai; Chin-Ying;
(Hsinchu City, TW) |
Assignee: |
INDUSTRIAL TECHNOLOGY RESEARCH
INSTITUTE
Hsinchu County
TW
|
Family ID: |
44187917 |
Appl. No.: |
13/041412 |
Filed: |
March 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12118693 |
May 10, 2008 |
|
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13041412 |
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Current U.S.
Class: |
428/220 ;
106/206.1; 106/215.1; 106/215.5; 106/217.2; 106/217.3; 524/53;
536/106 |
Current CPC
Class: |
C08J 9/0061 20130101;
C08L 2201/06 20130101; C08J 2303/02 20130101; C08L 29/04 20130101;
C08J 2203/06 20130101; C08L 3/06 20130101; C08B 31/04 20130101;
C08J 2429/00 20130101; C08J 5/18 20130101; C08J 9/0066 20130101;
C08J 9/0023 20130101; C08B 31/003 20130101; C08J 2201/03 20130101;
C08J 9/125 20130101; C08J 2399/00 20130101 |
Class at
Publication: |
428/220 ;
536/106; 106/206.1; 106/217.2; 106/217.3; 106/215.1; 524/53;
106/215.5 |
International
Class: |
B32B 5/00 20060101
B32B005/00; C08B 31/00 20060101 C08B031/00; C09D 103/04 20060101
C09D103/04; C09D 129/04 20060101 C09D129/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2007 |
TW |
96150509 |
Claims
1. A biodegradable starch film, comprising: a starch which is
cross-linked by means of a cross-linking agent, wherein the
cross-linking agent comprises glycidyl methacrylate 2,3-epoxypropyl
methacrylate (GMA), octenyl succinyl anhydride (OSA), or dodecyl
succinic anhydride (DDSA) or combinations thereof, wherein the
cross-linking agent is 1 to 10 weight parts based on the starch of
100 weight parts.
2. The biodegradable starch film as claimed in claim 1, wherein the
starch comprises a cereal, or a root crop.
3. The biodegradable starch film as claimed in claim 2, wherein the
cereal includes rice, wheat or corn.
4. The biodegradable starch film as claimed in claim 1, which has a
thickness of between 0.02 and 0.10 mm.
5. The biodegradable starch film as claimed in claim 1, which has a
moisture content of between 2 and 15%.
6. The biodegradable starch film as claimed in claim 1, which has a
water vapor transmission rate of between 5.2*10.sup.-3 and
9.8*10.sup.-3 gm.sup.-2s.sup.-1.
7. The biodegradable starch film as claimed in claim 1, which has a
water vapor permeability of between 10.5*10.sup.-11 and
19.6*10.sup.-11 gm.sup.-2s.sup.-1Pa.sup.-1.
8. A method for manufacturing starch foam, comprising: modifying a
starch by a cross-linking agent, wherein the cross-linking agent
comprises glycidyl methacrylate 2,3-epoxypropyl methacrylate (GMA),
octenyl succinyl anhydride (OSA), or dodecyl succinic anhydride
(DDSA) or combinations thereof, and the cross-linking agent is 1 to
10 weight parts based on the starch of 100 weight parts; mixing the
modified starch with a nucleating agent and a foaming agent to form
a foamable mixture; and foaming the foamable mixture to form a
foam.
9. The method as claimed in claim 8, wherein the starch comprises a
cereal, or a root crop.
10. The method as claimed in claim 9, wherein the cereal includes
rice, wheat or corn.
11. The method as claimed in claim 8, wherein the nucleating agent
comprises calcium carbonate, calcium hydroxide or silicate.
12. The method as claimed in claim 8, wherein the foaming agent
comprises water, carbon dioxide, nitrogen, oxygen, air or
alcohol.
13. The method as claimed in claim 8, wherein the modified starch
further mixes with an additive, a plasticizing agent or
combinations thereof.
14. The method as claimed in claim 13, wherein the additive
comprises polyvinyl alcohol.
15. The method as claimed in claim 13, wherein the plasticizing
agent comprises glycerol.
16. The method as claimed in claim 8, wherein the foaming step
comprises mold press foaming or extrusion foaming.
17. The method as claimed in claim 16, wherein the mold press
foaming and the extrusion foaming are performed at a temperature of
120-180.degree. C.
18. The method as claimed in claim 8, wherein the starch foam has a
biodegradation lower than 10% in a duration of 180 days.
Description
[0001] This application is a Continuation-In-Part of pending U.S.
patent application Ser. No. 12/118,693 filed May, 10, 2008 and
entitled "Methods for Manufacturing Starch Foam", which claims
priority of Taiwan Patent Application No. 96150509, filed on Dec.
27, 2007, the entirety of which is incorporated by reference
herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a starch film and a method for
manufacturing a starch foam.
[0004] 2. Description of the Related Art
[0005] The Waste Electrical and Electronic Equipment (WEEE)
Directive (European Community directive 2002/96/EC) and the
Restriction of Hazardous Substance (RoHS) Directive (European
Community directive 2002/95/EC) have been published by the European
Union (EU) since 2003, and obliges EU member states to transpose
its provisions into national law for setting collection, recycling
and recovery targets for all types of electrical goods. As of July
2006, the maximum weight for the substances of lead, mercury,
cadmium, chromium (VI), polybrominated biphenyls (PBB) and
polybrominated diphenyl ethers (PBDE) are prohibited by the RoHS
Directive. If an electronic equipment has these substances which
exceed the limit, the electronic equipment will not be allowed into
EU member states. Manufacturing products in consideration of
environmental friendliness (or so-called "green products`) is a
major subject for the manufacturing industry. For green products,
all parts of a product must conform to the proper directives. As
such, manufacturing techniques specifically geared toward green
products have increased in demand due to environmental
friendliness.
[0006] With conventional plastics seldom being hard to
self-decompose, they cause environmental issues when discarded.
Thus, degradable plastics have been imported, researched and
manufactured in many countries. Recently, developed countries have
increased research for eco-materials, such as environmentally
friendly materials. Meanwhile, cheap materials, such as PVC and
EPS, are the main packaging materials previously used. Since PVC
contains chlorine, it causes an environment issue during its whole
life cycle, such as during production, use, and when discarded. PVC
is called a "poison plastic" by Greenpeace International, and is
deemed not fit for environmental demands. Thus, PVC has been
substituted by polyolefin. However, no suitable material has been
developed, that would feasibly be a substitute for ESP. Thus,
increased methods for manufacturing and modeling materials which
can be popularly or specially applied should be developed to meet
demands for lower costs, recycling capabilities and environmental
friendliness.
[0007] For example, cellulose, starch and chitosan are natural
materials which can be decomposed in nature. In particular, starch
is one of the best biodegradable raw materials due to its good
processability and biodegradability.
[0008] Starch is a hydrophilic polymer and the hydroxyl groups
therein react with the hydrogen bond of water. Thus, plastics
formed of pure starch are not suitable for an environment with
moisture. To address this issue, one solution is to mix the starch
with hydrophobic polymers to improve water resistance. However, the
compositions have shortcomings as performing uniform mixing is
difficult and combining of the starch and the hydrophobic polymers
may be weak.
[0009] Therefore, a starch composition capable of addressing the
above issues is desired.
BRIEF SUMMARY OF INVENTION
[0010] A detailed description is given in the following embodiments
with reference to the accompanying drawings.
[0011] The present invention provides an embodiment of a
biodegradable starch film. The biodegradable starch film includes a
starch which is cross-linked by means of a cross-linking agent. The
cross-linking agent includes glycidyl methacrylate 2,3-epoxypropyl
methacrylate (GMA), octenyl succinyl anhydride (OSA), or dodecyl
succinic anhydride (DDSA) or combinations thereof. The
cross-linking agent is 1 to 10 weight parts based on the starch of
100 weight parts.
[0012] The present invention provides another embodiment of a
method for manufacturing starch foam. The method includes modifying
a starch by a cross-linking agent, wherein the cross-linking agent
includes glycidyl methacrylate 2,3-epoxypropyl methacrylate (GMA),
octenyl succinyl anhydride (OSA), or dodecyl succinic anhydride
(DDSA) or combinations thereof. The cross-linking agent is 1 to 10
weight parts based on the starch of 100 weight parts. The modified
starch is mixed with a nucleating agent and a foaming agent to form
a foamable mixture. The foamable mixture is foamed to form a
foam.
BRIEF DESCRIPTION OF DRAWINGS
[0013] The present invention can be more fully understood by
reading the subsequent detailed description and examples with
references made to the accompanying drawings, wherein:
[0014] FIGS. 1(a) and 1(b) show the SEM images of the modified
starch film in Example 1 and the non-modified starch film in
Comparative Example 1, respectively.
[0015] FIG. 2 illustrates a schematic view showing a biodegradation
test system according to an embodiment of the invention.
DETAILED DESCRIPTION OF INVENTION
[0016] A starch film and a method for manufacturing a starch foam
of the present invention are described in detail as follows. The
starch film may comprise a starch modified by a cross-linking
agent. The starch may include a cereal or a root crop. The cereal
may include rice, wheat, corn or other natural cereal plants. The
root crop may include cassava, sweet potato, potato or other
natural root crop plants. In addition to the cereal and the root
crop, the starch may also include any plant having starch
elements.
[0017] The starch has at least two hydroxyl groups capable of
reacting with the cross-linking agent. Thus, by using the
cross-linking agent, the hydroxyl groups of the starch may be
transformed to hydrophobic groups resulting in improved water
resistance of the modified starch. For example, the starch may be
preferably modified by an epoxy cross-linking agent or an acid
anhydride cross-linking agent, wherein the carbon numbers of the
cross-linking agent are between 5 and 20 weight parts, preferably
between 5 and 10 weight parts based on the starch of 100 weight
parts. In the present embodiment, the cross-linking agent may be
glycidyl methacrylate 2,3-epoxypropyl methacrylate (GMA), octenyl
succinyl anhydride (OSA), or dodecyl succinic anhydride (DDSA) or
combinations thereof. The cross-linking agent is 1 to 10 weight
parts based on the starch of 100 weight parts.
[0018] Furthermore, the hydrogen bonds between the starches may be
replaced with covalent bonds by means of the cross-linking agent
such that stronger bonding (e.g., ester bond) and longer paths may
be formed between the starches. The starches are highly
cross-linked. Thus, the water penetrating path increases in length
and the water vapor transmission rate is reduced.
[0019] For example, the starch film may have a thickness of between
0.02 and 0.10 mm. In one embodiment, the starch film may have a
water vapor transmission rate of between 5.2*10.sup.-3 and
9.8*10.sup.-3 gm.sup.-2s.sup.-1, and may have a water vapor
permeability of between 10.5*10.sup.-11 and 19.6*10.sup.-11
gm.sup.-2s.sup.-1Pa.sup.-1.
[0020] In addition, a starch foam may be formed from the modified
starch. The starch foam may include the modified starch, a
nucleating agent, and a foaming agent. In one embodiment, the
nucleating agent may include calcium carbonate, calcium hydroxide,
silicate or other suitable nucleating agents. The nucleating agent
is 0.1 to 20 weight parts based on the modified starch of 100
weight parts. The foaming agent may include water, carbon dioxide,
nitrogen, oxygen, air, alcohol or other suitable foaming agents.
The foaming agent is 0.1 to 20 weight parts based on the modified
starch of 100 weight parts.
[0021] In addition to the modified starch, the nucleating agent,
and the foaming agent, the starch foam may further include an
additive and/or a plasticizing agent. The additive may include
polyvinyl alcohol or other suitable additives. The additive is 0 to
50 weight parts based on the modified starch 100 weight parts. The
plasticizing agent may include glycerol or other suitable
plasticizing agents. The plasticizing agent is 0 to 30 weight parts
based on the modified starch of 100 weight parts.
[0022] The starch foam is formed by the following steps: (a) the
weighted modified starch and the weighted nucleating agent are put
into a high speed mixer for mixing with a high speed of 3000 rpm
for 1 minute and then left standing for 5 minutes, (b) the foaming
agent, or appropriately the additive, the plasticizing agent and
the cross-linking agent are put into the high speed mixture for
mixing with a high speed of 3000 rpm for 3 minutes and then left
standing for 5 minutes, mixing with a high speed of 3000 rpm for 3
minutes and then left standing for 5 minutes, and mixing with a
high speed of 3000 rpm for 3 minutes and then left standing for 10
minutes, in sequence. Therefore the mixture is mixed to form the
foamable mixture.
[0023] Next, the foamable mixture is foamed to form the foam. The
foaming step includes mold press foaming or extrusion foaming. The
mold compression foaming step includes pressing the foamable
mixture, weighted by the electronic control system, into a mold by
a hydraulic press system, and then mold compression foaming the
foamable mixture at a pressure of 20-100 kg/cm.sup.2 and a
temperature of 120-180.degree. C. to form the foam. The extrusion
foaming step includes kneading the foamable mixture into grain by a
twin-screw extruder, and then extrusion foaming the grain foamable
mixture to form the foam by a single-screw extruder at a
temperature of 120-180.degree. C.
[0024] The following description is of the best-contemplated mode
of carrying out the invention. This description is made for the
purpose of illustrating the general principles of the invention and
should not be taken in a limiting sense. The scope of the invention
is best determined by reference to the appended claims.
Example 1
[0025] A corn starch-aqueous alcohol suspension was prepared and 3
weight parts of glycidyl methacrylate 2,3-epoxypropyl methacrylate
(GMA) (based on 100 weight parts of the corn starch) was added to
the suspension. The suspension was stirred under N.sub.2 at room
temperature for 3 hours. Then, the suspension was stirred at
95.degree. C. for 1 hour and gradually transformed to a gel.
Finally, the gel was placed in a petri dish and dried at 60.degree.
C. for 3 hours to obtain a GMA modified starch film. The thickness,
moisture content, water vapor transmission rate and water vapor
permeability of the GMA modified starch film is shown in Table
1.
Example 2
[0026] A corn starch-aqueous alcohol suspension was prepared and 5
weight parts of octenyl succinyl anhydride (OSA) (based on 100
weight parts of the corn starch) was added to the suspension. The
pH value of the suspension was adjusted to about 8 and the
suspension was stirred at room temperature for 24 hours. Then, the
suspension was stirred at 80.degree. C. for 1 hour and then at
95.degree. C. for 1 hour. The suspension was gradually transformed
to a gel. Finally, the gel was placed in a petri dish and dried at
60.degree. C. for 3 hours to obtain an OSA modified starch film.
The thickness, moisture content, water vapor transmission rate and
water vapor permeability of the OSA modified starch film is shown
in Table 1.
Example 3
[0027] A corn starch-aqueous alcohol suspension was prepared and
its pH value was adjusted to 2.5. 7 weight parts of dodecyl
succinic anhydride (DDSA) (based on 100 weight parts of the corn
starch) was added to the suspension. The pH value of the suspension
was adjusted to about 8 and the suspension was stirred at
35.degree. C. for 3 hours. Then, the suspension was stirred at
80.degree. C. for 1 hour and then at 95.degree. C. for 1 hour. The
suspension was gradually transformed to a gel. Finally, the gel was
placed in a petri dish and dried at 60.degree. C. for 3 hours to
obtain a DDSA modified starch film. The thickness, moisture
content, water vapor transmission rate and water vapor permeability
of the DDSA modified starch film is shown in Table 1.
Comparative Example 1
[0028] A corn starch-aqueous alcohol suspension was prepared. Then,
the suspension was stirred at 80.degree. C. for 1 hour and then at
95.degree. C. for 10 minutes. The suspension was gradually
transformed to a gel. Finally, the gel was placed in a petri dish
and dried at 60.degree. C. for 3 hours to obtain a starch film. The
thickness, moisture content, water vapor transmission rate and
water vapor permeability of the starch film is shown in Table
1.
TABLE-US-00001 TABLE 1 Characteristics of the starch films in
Examples 1-3 and Comparative Examples 1-3 Water vapor Water vapor
Moisture transmission permeability Thickness content rate
(10.sup.-3 * (10.sup.-11 * (mm) (%) gm.sup.-2s.sup.-1)
gm.sup.-2s.sup.-1Pa.sup.-1) Example 1 (GMA) 0.055 3.4 6.5 11.2
Example 2 (OSA) 0.065 6.8 7.2 14.6 Example 3 (DDSA) 0.06 4.6 6.9
12.9 Comparative 0.065 9.2 7.8 15.8 Example 1 (non- modified)
[0029] As shown in Table 1, each of the modified starch films in
Examples 1-3 had a water content much lower than the non-modified
starch film in Comparative Example 1. In particular, the GMA
modified starch film in Example 1 had a moisture content as low as
3.4% which is only about 1/3 of that of the non-modified starch
film. Furthermore, the water vapor transmission rate and the water
vapor permeability of each of the modified starch films in Examples
1-3 were also much lower than that of the non-modified starch film.
From these results, it can be suggested that the starch film
modified by the cross-linking agent may lead to the starch film
being more hydrophobic and having longer paths for water
penetration. Thus, the water resistance of the modified starch film
was significantly improved.
[0030] FIGS. 1(a) and 1(b) show the SEM images of the modified
starch film in Example 1 and the non-modified starch film in
Comparative Example 1, respectively. As shown in FIG. 1(a), it can
be seen that block shaped structures of the modified starches were
formed from the small starch particles shown in FIG. 1(b) after
cross-linking. The longer paths between the starches for water
penetration were clearly shown in the SEM images.
Examples 4-6
[0031] Powdery rice, calcium carbonate of the nucleating agent,
glycerol of the plasticizing agent, water of the foaming agent, and
GMA, OSA, DDSA of the cross-linking agent with ratios as shown in
Tables 2.about.4, respectively, were well mixed to form a foamable
mixture. The foamable mixture, weighted by using the electronic
control system, was then pressed into the mold by using the
hydraulic press system. Next, the foamable mixture was mold
compression foamed to form the foam at a pressure of 20-100
kg/cm.sup.2 and temperature of 120-180.degree. C. The results of
the Examples 4.about.6 are shown in Table 9.
Comparative Examples 2.about.4
[0032] Powdery rice, calcium carbonate of the nucleating agent,
glycerol of the plasticizing agent, water of the foaming agent, and
ethylene dialdehyde monomer, acetic anhydride monomer, methyl
methacrylate monomer of the cross-linking agent with ratios as
shown in Tables 5.about.7, respectively, were well mixed to form a
foamable mixture. The foamable mixture, weighted by using the
electronic control system, was then pressed into the mold by using
the hydraulic press system. Next, the foamable mixture was mold
compression foamed to form the foam at a pressure of 20.about.100
kg/cm.sup.2 and temperature of 120-180.degree. C. The results of
the Comparative Examples 2-4 are shown in Table 9.
Comparative Example 5
[0033] Powdery rice, calcium carbonate of a nucleating agent,
glycerol of a plasticizing agent, and water of a foaming agent were
well mixed with ratios as shown in Table 8 to form a foamable
mixture. The foamable mixture, weighted by the electronic control
system, was pressed into the mold by using the hydraulic press
system. Next, the foamable mixture was mold compression foamed form
the foam at a pressure of 20-100 kg/cm.sup.2 and temperature of
120-180.degree. C. The result of the Comparative Example 5 is shown
in Table 9.
TABLE-US-00002 TABLE 2 The components of the mixture for the
Example 4 component weight (powdery) rice 100 calcium carbonate 8
glycerol 5 GMA 5 water 30
TABLE-US-00003 TABLE 3 The components of the mixture for the
Example 5 component weight (powdery) rice 100 calcium carbonate 8
glycerol 5 OSA 5 water 30
TABLE-US-00004 TABLE 4 The components of the mixture for the
Example 6 component weight (powdery) rice 100 calcium carbonate 8
glycerol 5 DDSA 5 water 30
TABLE-US-00005 TABLE 5 The components of the mixture for the
Comparative Example 2 component weight (powdery) rice 100 calcium
carbonate 8 glycerol 5 Ethylene dialdehyde 5 monomer water 30
TABLE-US-00006 TABLE 6 The components of the mixture for the
Comparative Example 3 component weight (powdery) rice 100 calcium
carbonate 8 glycerol 5 Acetic anhydride monomer 5 water 30
TABLE-US-00007 TABLE 7 The components of the mixture for the
Comparative Example 4 component weight (powdery) rice 100 calcium
carbonate 8 glycerol 5 Methyl methacrylate 5 monomer water 30
TABLE-US-00008 TABLE 8 The components of the mixture for the
Comparative Example 5 component weight (powdery) rice 100 calcium
carbonate 8 glycerol 5 water 30
TABLE-US-00009 TABLE 9 Characteristics of EPS, and foams formed by
the method according to the Examples 4~6 and Comparative Examples
2~5 Comparative Comparative Comparative Comparative Example 4
Example 5 Example 6 Example 2 Example 3 Example 4 Example 5 EPS
density (g/cm.sup.3) 0.182 0.153 0.178 0.222 0.232 0.242 0.213
0.021 pH value 6.8 6.5 6.7 6.3 6.2 6.8 7.0 7.2 dimension change (%)
+0.3 +0.3 +0.3 +0.5 +0.5 +0.5 +0.6 +0.4 compressive strength 5.73
4.12 4.86 3.18 3.26 3.47 2.82 2.18 (kgf/cm.sup.2) biodegradation
(%/day) >70/45 >70/45 >70/45 >70/45 >70/45 >70/45
>70/45 <10/180
[0034] The experimental results, illustrated in Table 9, show that
the compressive strength of the foams formed by the methods
according to the examples is stronger than that of the dialdehyde
monomer, anhydride monomer, and acrylic monomer. Thus, the foams
formed by the methods according to the examples withstood higher
stress even with less density. Biodegradation tests were performed
according to the CNS144321 national standard. The EPS and the foams
of the Examples 4.about.6 and Comparative Examples 2.about.5 were
tested for aerobic biodegradation and the disintegration, and
analyzed for carbon dioxide liberation, in a muck environment by
the method as shown in FIG. 2. An air 1 was flowed into a de-carbon
dioxide system 7 containing a sodium hydroxide solution 6 to form
an air without carbon dioxide 2. The air without carbon dioxide 2
was flowed into a muck container 8 containing a test compound 5,
and was decomposed by the test compound 5 to form an air with
carbon dioxide 3. The air with carbon dioxide 3 was tested for a
quantity of carbon dioxide by a carbon dioxide test system 9. The
test foams were put in a muck container 8 at a stable temperature
of 58.+-.2.degree. C. and isolated from vapor that may affect
organisms. The test was designed for the conversion ratio of the
carbon elements of the test foams into the carbon dioxide. The
duration of the test was generally 180 days. The biodegradation of
the foams, formed by the methods according to the examples 4, 5,
and 6, were 70% in the duration of only 45 days. Thus, the foams
were defined as being biodegradable according to the CNS 144321
national standard. However, the biodegradation of the conventional
EPS was lower than 10% in the duration of 180 days, thus showing
that the conventional EPS does affect the global environment. Since
the foams of the invention are manufactured using the cereal or the
root crop of natural plants by the method according to the
invention, the foams of the invention do not cause environmental
pollution issues.
[0035] While the invention has been described by way of example and
in terms of the preferred embodiments, it is to be understood that
the invention is not limited to the disclosed embodiments. To the
contrary, it is intended to cover various modifications and similar
arrangements (as would be apparent to those skilled in the art).
Therefore, the scope of the appended claims should be accorded the
broadest interpretation so as to encompass all such modifications
and similar arrangements.
* * * * *